Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
1.
Int J Mol Sci ; 22(12)2021 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-34207287

RESUMEN

Gastrodia elata is a well-known medicinal and heterotrophic orchid. Its germination, limited by the impermeability of seed coat lignin and inhibition by abscisic acid (ABA), is triggered by symbiosis with fungi such as Mycena spp. However, the molecular mechanisms of lignin degradation by Mycena and ABA biosynthesis and signaling in G. elata remain unclear. In order to gain insights into these two processes, this study analyzed the transcriptomes of these organisms during their dynamic symbiosis. Among the 25 lignin-modifying enzyme genes in Mycena, two ligninolytic class II peroxidases and two laccases were significantly upregulated, most likely enabling Mycena hyphae to break through the lignin seed coats of G. elata. Genes related to reduced virulence and loss of pathogenicity in Mycena accounted for more than half of annotated genes, presumably contributing to symbiosis. After coculture, upregulated genes outnumbered downregulated genes in G. elata seeds, suggesting slightly increased biological activity, while Mycena hyphae had fewer upregulated than downregulated genes, indicating decreased biological activity. ABA biosynthesis in G. elata was reduced by the downregulated expression of 9-cis-epoxycarotenoid dioxygenase (NCED-2), and ABA signaling was blocked by the downregulated expression of a receptor protein (PYL12-like). This is the first report to describe the role of NCED-2 and PYL12-like in breaking G. elata seed dormancy by reducing the synthesis and blocking the signaling of the germination inhibitor ABA. This study provides a theoretical basis for screening germination fungi to identify effective symbionts and for reducing ABA inhibition of G. elata seed germination.


Asunto(s)
Ácido Abscísico/metabolismo , Agaricales/patogenicidad , Proteínas Fúngicas/genética , Gastrodia/microbiología , Lignina/metabolismo , Proteínas de Plantas/genética , Agaricales/genética , Agaricales/metabolismo , Dioxigenasas/genética , Dioxigenasas/metabolismo , Proteínas Fúngicas/metabolismo , Gastrodia/genética , Gastrodia/crecimiento & desarrollo , Gastrodia/metabolismo , Germinación , Lacasa/genética , Lacasa/metabolismo , Lignina/genética , Peroxidasas/genética , Peroxidasas/metabolismo , Proteínas de Plantas/metabolismo , Simbiosis , Transcriptoma
2.
Fungal Genet Biol ; 126: 50-55, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30794952

RESUMEN

The fungus Moniliophthora perniciosa is the causal agent of witches' broom disease (WBD), one of the most devastating diseases of cacao, the chocolate tree. Many strategies to control WBD have been tested so far, including the use of agrochemicals such as the strobilurins. Strobilurins are fungicides of the QoI family, and they are used in the control of a wide array of fungal diseases in many different crops, including cereals, field crops, fruits, tree nuts, and vegetables. These drugs act by specifically inhibiting fungal respiration at the Qo site of complex III, which is a component of the main mitochondrial respiratory chain. However, M. perniciosa is resistant to this family of chemicals. It has been postulated that this resistant phenotype is, at least in part, a result of the strong ability of this fungus to counteract the oxidative stress generated by the impairment of the main mitochondrial respiratory chain, through the activation of an alternative oxidase (Mp-AOX). To test this hypothesis, we expressed functional mitochondria-localized Mp-AOX in the model yeast Saccharomyces cerevisiae. We demonstrated that heterologous expression of Mp-AOX strongly inhibits hydrogen peroxide production by mitochondria. It also diminishes the total cell amount of oxidized glutathione (GSSG), resulting in a fifty-fold higher GSH/GSSG ratio in cells expressing Mp-AOX than in wild type cells. In addition, Mp-AOX activity decreases yeast growth rate and leads to low biomass production. Therefore, we propose the use of this heterologous expression system to direct the development of new inhibitors of fungal AOX by comparing the differences in optical density of Mp-AOX-expressing cells in the presence and absence of potential AOX inhibitors. Together, our results confirm the antioxidant role of Mp-AOX and provide an in vivo platform to be used in the screening of new fungicides based on Mp-AOX inhibition.


Asunto(s)
Agaricales/enzimología , Agaricales/patogenicidad , Antioxidantes/metabolismo , Proteínas Fúngicas/genética , Proteínas Mitocondriales/genética , Oxidorreductasas/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/genética , Fungicidas Industriales , Mitocondrias/metabolismo , Estrés Oxidativo , Saccharomyces cerevisiae/genética
3.
J Nat Prod ; 82(1): 122-128, 2019 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-30457333

RESUMEN

Three new macrocyclic trichothecenes (1-3) and five known related compounds (4-8) were isolated from the MeOH extract of a plate culture of the fungus Podostroma cornu-damae, a deadly poisonous mushroom. Miophytocen D (1) is a rearranged macrocyclic type D trichothecene, featuring a bicyclo-[6.5]dodecahydrocyclopenta[ b]chromene scaffold, and the structures of new compounds (1-3) were delineated by the combination of 1D and 2D NMR spectroscopic experiments and HRESIMS, modified Mosher's esterification, and quantum chemical ECD calculations. The isolated compounds (1-8) were evaluated for cytotoxicity against four human breast cancer cell lines (Bt549, HCC70, MDA-MB-231, and MDA-MB-468). Compounds 4, 6, and 8 exhibited significant cytotoxic effects against the breast cancer cell lines, with IC50 values in the range of 0.02-80 nM, which is stronger than doxorubicin, the positive control, and a structure-activity relationship was suggested.


Asunto(s)
Agaricales/patogenicidad , Micotoxinas/aislamiento & purificación , Tricotecenos/aislamiento & purificación , Antineoplásicos/farmacología , Línea Celular Tumoral , Humanos , Espectroscopía de Resonancia Magnética , Relación Estructura-Actividad , Tricotecenos/química , Tricotecenos/farmacología
4.
Phytopathology ; 109(8): 1331-1343, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31115251

RESUMEN

Theobroma cacao, the source of chocolate, is affected by destructive diseases wherever it is grown. Some diseases are endemic; however, as cacao was disseminated from the Amazon rain forest to new cultivation sites it encountered new pathogens. Two well-established diseases cause the greatest losses: black pod rot, caused by several species of Phytophthora, and witches' broom of cacao, caused by Moniliophthora perniciosa. Phytophthora megakarya causes the severest damage in the main cacao producing countries in West Africa, while P. palmivora causes significant losses globally. M. perniciosa is related to a sister basidiomycete species, M. roreri which causes frosty pod rot. These Moniliophthora species only occur in South and Central America, where they have significantly limited production since the beginnings of cacao cultivation. The basidiomycete Ceratobasidium theobromae causing vascular-streak dieback occurs only in South-East Asia and remains poorly understood. Cacao swollen shoot disease caused by Cacao swollen shoot virus is rapidly spreading in West Africa. This review presents contemporary research on the biology, taxonomy and genomics of what are often new-encounter pathogens, as well as the management of the diseases they cause.


Asunto(s)
Agaricales , Cacao , Chocolate , Agaricales/patogenicidad , Basidiomycota , Cacao/microbiología , Enfermedades de las Plantas/microbiología
5.
J Biol Chem ; 292(50): 20558-20569, 2017 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-29042440

RESUMEN

Moniliophthora perniciosa is the causative agent of witches' broom disease, which devastates cacao cultures in South America. This pathogenic fungus infects meristematic tissues and derives nutrients from the plant apoplast during an unusually long-lasting biotrophic stage. To survive, the fungus produces proteins to suppress the plant immune response. Proteins of the PR-1 (pathogenesis-related 1)/CAP superfamily have been implicated in fungal virulence and immune suppression. The genome of M. perniciosa encodes 11 homologues of plant PR-1 proteins, designated MpPR-1 proteins, but their precise mode of action is poorly understood. In this study, we expressed MpPR-1 proteins in a yeast model lacking endogenous CAP proteins. We show that some members of the MpPR-1 family bind and promote secretion of sterols, whereas others bind and promote secretion of fatty acids. Lipid binding by purified MpPR-1 occurs with micromolar affinity and is saturable in vitro Sterol binding by MpPR-1 requires the presence of a flexible loop region containing aromatic amino acids, the caveolin-binding motif. Remarkably, MpPR-1 family members that do not bind sterols can be converted to sterol binders by a single point mutation in the caveolin-binding motif. We discuss the possible implications of the lipid-binding activity of MpPR-1 family members with regard to the mode of action of these proteins during M. perniciosa infections.


Asunto(s)
Agaricales/metabolismo , Ácidos Grasos no Esterificados/metabolismo , Proteínas Fúngicas/metabolismo , Esteroles/metabolismo , Agaricales/química , Agaricales/patogenicidad , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Unión Competitiva , Cacao/microbiología , Colesterol/química , Colesterol/metabolismo , Ácidos Grasos no Esterificados/química , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Eliminación de Gen , Cinética , Ligandos , Mutagénesis Sitio-Dirigida , Ácido Palmítico/química , Ácido Palmítico/metabolismo , Mutación Puntual , Conformación Proteica , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Esteroles/química
6.
Drug Chem Toxicol ; 41(4): 459-464, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29359595

RESUMEN

This study aimed to establish an in vitro model to confirm the efficacy of erinacine A-enriched Hericium erinaceus (EAHE) mycelia and investigate its potential adverse effects in a preclinical experimental setting, including an assessment on the oral administration of EAHE mycelia in acute and prenatal developmental toxicity tests. At a single dose of 5000 mg/kg body weight, EAHE mycelia elicited no death or treatment-related signs of toxicity in ten Sprague-Dawley rats of both sexes during the 14 days of the experimental period. After considering the recommended dose range of EAHE mycelia from the acute toxicity test as well as the therapeutic doses, EAHE mycelia was administered to 66 pregnant rats in the low, medium, and high-dose groups by gavage at 875, 1750, and 2625 mg/kg body weight, respectively. All dams were subjected to a Caesarean section on the 20th day of pregnancy, and the fetuses were examined for any morphological abnormalities. Results indicated that weight of uterus, fetal body weight, number of corpora lutea, implantation sites, pre-implantation loss, and post-implantation loss of the treatment groups and the control group exhibited no statistical difference. In addition, no significant differences were observed in the fetal external, organ, and skeletal examinations. Taken together, it can be concluded that EAHE mycelia is considered safe and practically nontoxic for consumption within the appropriate doses and investigation period in this study.


Asunto(s)
Agaricales/patogenicidad , Desarrollo Fetal/efectos de los fármacos , Micelio/patogenicidad , Animales , Femenino , Masculino , Embarazo , Ratas , Ratas Sprague-Dawley , Pruebas de Toxicidad Aguda
7.
BMC Microbiol ; 17(1): 176, 2017 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-28818052

RESUMEN

BACKGROUND: Moniliophthora perniciosa is a phytopathogenic fungus responsible for witches' broom disease of cacao trees (Theobroma cacao L.). Understanding the molecular events during germination of the pathogen may enable the development of strategies for disease control in these economically important plants. In this study, we determined a comparative proteomic profile of M. perniciosa basidiospores during germination by two-dimensional SDS-PAGE and mass spectrometry. RESULTS: A total of 316 proteins were identified. Molecular changes during the development of the germinative tube were identified by a hierarchical clustering analysis based on the differential accumulation of proteins. Proteins associated with fungal filamentation, such as septin and kinesin, were detected only 4 h after germination (hag). A transcription factor related to biosynthesis of the secondary metabolite fumagillin, which can form hybrids with polyketides, was induced 2 hag, and polyketide synthase was observed 4 hag. The accumulation of ATP synthase, binding immunoglobulin protein (BiP), and catalase was validated by western blotting. CONCLUSIONS: In this study, we showed variations in protein expression during the early germination stages of fungus M. perniciosa. Proteins associated with fungal filamentation, and consequently with virulence, were detected in basidiospores 4 hag., for example, septin and kinesin. We discuss these results and propose a model of the germination of fungus M. perniciosa. This research can help elucidate the mechanisms underlying basic processes of host invasion and to develop strategies for control of the disease.


Asunto(s)
Agaricales/genética , Agaricales/metabolismo , Cacao/microbiología , Cytisus/metabolismo , Germinación/genética , Enfermedades de las Plantas/microbiología , Proteómica , Agaricales/patogenicidad , Catalasa/metabolismo , Análisis por Conglomerados , Ciclohexanos/metabolismo , Cytisus/microbiología , Ácidos Grasos Insaturados/metabolismo , Proteínas Fúngicas/genética , Germinación/fisiología , Sintasas Poliquetidas/metabolismo , Policétidos/metabolismo , Metabolismo Secundario , Alineación de Secuencia , Sesquiterpenos/metabolismo , Esporas Fúngicas/metabolismo , Factores de Transcripción , Virulencia
8.
Plant Cell ; 26(11): 4245-69, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25371547

RESUMEN

Witches' broom disease (WBD), caused by the hemibiotrophic fungus Moniliophthora perniciosa, is one of the most devastating diseases of Theobroma cacao, the chocolate tree. In contrast to other hemibiotrophic interactions, the WBD biotrophic stage lasts for months and is responsible for the most distinctive symptoms of the disease, which comprise drastic morphological changes in the infected shoots. Here, we used the dual RNA-seq approach to simultaneously assess the transcriptomes of cacao and M. perniciosa during their peculiar biotrophic interaction. Infection with M. perniciosa triggers massive metabolic reprogramming in the diseased tissues. Although apparently vigorous, the infected shoots are energetically expensive structures characterized by the induction of ineffective defense responses and by a clear carbon deprivation signature. Remarkably, the infection culminates in the establishment of a senescence process in the host, which signals the end of the WBD biotrophic stage. We analyzed the pathogen's transcriptome in unprecedented detail and thereby characterized the fungal nutritional and infection strategies during WBD and identified putative virulence effectors. Interestingly, M. perniciosa biotrophic mycelia develop as long-term parasites that orchestrate changes in plant metabolism to increase the availability of soluble nutrients before plant death. Collectively, our results provide unique insight into an intriguing tropical disease and advance our understanding of the development of (hemi)biotrophic plant-pathogen interactions.


Asunto(s)
Agaricales/fisiología , Cacao/genética , Interacciones Huésped-Patógeno , Enfermedades de las Plantas/microbiología , Transcriptoma , Agaricales/patogenicidad , Secuencia de Bases , Cacao/citología , Cacao/microbiología , Análisis por Conglomerados , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Secuenciación de Nucleótidos de Alto Rendimiento , Modelos Biológicos , Datos de Secuencia Molecular , Micelio , Fotosíntesis , Proteínas de Plantas/metabolismo , Análisis de Secuencia de ARN , Virulencia
9.
Transpl Infect Dis ; 18(4): 611-6, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27237466

RESUMEN

Disseminated infection by Hormographiella aspergillata is extremely rare and small intestine involvement has not been reported previously. A 51-year-old man with myelodysplastic syndrome developed pneumonia after cord blood cell transplantation. Fungal growth from the biopsied lung was identified as H. aspergillata by morphology and the gene analysis. Although antifungal agents including voriconazole and liposomal amphotericin B were administered, he died of disseminated H. aspergillata infection. We review the literature and discuss the treatment and prognosis.


Asunto(s)
Agaricales/patogenicidad , Antifúngicos/uso terapéutico , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Terapia de Inmunosupresión/efectos adversos , Infecciones Fúngicas Invasoras/microbiología , Enfermedades Raras/microbiología , Agaricales/genética , Agaricales/aislamiento & purificación , Antifúngicos/administración & dosificación , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Infecciones Fúngicas del Sistema Nervioso Central/sangre , Infecciones Fúngicas del Sistema Nervioso Central/tratamiento farmacológico , Infecciones Fúngicas del Sistema Nervioso Central/etiología , Infecciones Fúngicas del Sistema Nervioso Central/patología , ADN de Hongos , Enfermedad Injerto contra Huésped/prevención & control , Humanos , Terapia de Inmunosupresión/métodos , Inmunosupresores/administración & dosificación , Inmunosupresores/uso terapéutico , Enfermedades Intestinales/sangre , Enfermedades Intestinales/tratamiento farmacológico , Enfermedades Intestinales/etiología , Enfermedades Intestinales/patología , Intestino Delgado/patología , Infecciones Fúngicas Invasoras/sangre , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Enfermedades Pulmonares Fúngicas/sangre , Enfermedades Pulmonares Fúngicas/tratamiento farmacológico , Enfermedades Pulmonares Fúngicas/etiología , Enfermedades Pulmonares Fúngicas/patología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/cirugía , Neutropenia/tratamiento farmacológico , Neutropenia/etiología , Neutropenia/microbiología , Enfermedades Raras/sangre , Enfermedades Raras/tratamiento farmacológico , Análisis de Secuencia de ADN , Tomografía Computarizada por Rayos X , Acondicionamiento Pretrasplante/efectos adversos , Acondicionamiento Pretrasplante/métodos , Trasplante Homólogo/efectos adversos
10.
Anal Chem ; 87(24): 12298-305, 2015 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-26637047

RESUMEN

Direct analysis of microbial cocultures grown on agar media by desorption electrospray ionization mass spectrometry (DESI-MS) is quite challenging. Due to the high gas pressure upon impact with the surface, the desorption mechanism does not allow direct imaging of soft or irregular surfaces. The divots in the agar, created by the high-pressure gas and spray, dramatically change the geometry of the system decreasing the intensity of the signal. In order to overcome this limitation, an imprinting step, in which the chemicals are initially transferred to flat hard surfaces, was coupled to DESI-MS and applied for the first time to fungal cocultures. Note that fungal cocultures are often disadvantageous in direct imaging mass spectrometry. Agar plates of fungi present a complex topography due to the simultaneous presence of dynamic mycelia and spores. One of the most devastating diseases of cocoa trees is caused by fungal phytopathogen Moniliophthora roreri. Strategies for pest management include the application of endophytic fungi, such as Trichoderma harzianum, that act as biocontrol agents by antagonizing M. roreri. However, the complex chemical communication underlying the basis for this phytopathogen-dependent biocontrol is still unknown. In this study, we investigated the metabolic exchange that takes place during the antagonistic interaction between M. roreri and T. harzianum. Using imprint-DESI-MS imaging we annotated the secondary metabolites released when T. harzianum and M. roreri were cultured in isolation and compared these to those produced after 3 weeks of coculture. We identified and localized four phytopathogen-dependent secondary metabolites, including T39 butenolide, harzianolide, and sorbicillinol. In order to verify the reliability of the imprint-DESI-MS imaging data and evaluate the capability of tape imprints to extract fungal metabolites while maintaining their localization, six representative plugs along the entire M. roreri/T. harzianum coculture plate were removed, weighed, extracted, and analyzed by liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Our results not only provide a better understanding of M. roreri-dependent metabolic induction in T. harzianum, but may seed novel directions for the advancement of phytopathogen-dependent biocontrol, including the generation of optimized Trichoderma strains against M. roreri, new biopesticides, and biofertilizers.


Asunto(s)
4-Butirolactona/análogos & derivados , Agaricales/metabolismo , Productos Biológicos/análisis , Productos Biológicos/metabolismo , Butanos/metabolismo , Ciclohexanonas/metabolismo , Lactonas/metabolismo , Metabolismo Secundario , Trichoderma/metabolismo , 4-Butirolactona/química , 4-Butirolactona/aislamiento & purificación , 4-Butirolactona/metabolismo , Agaricales/crecimiento & desarrollo , Agaricales/patogenicidad , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Butanos/química , Butanos/aislamiento & purificación , Técnicas de Cocultivo , Ciclohexanonas/química , Ciclohexanonas/aislamiento & purificación , Lactonas/química , Lactonas/aislamiento & purificación , Espectrometría de Masa por Ionización de Electrospray , Trichoderma/crecimiento & desarrollo , Trichoderma/patogenicidad
11.
Biochem Biophys Res Commun ; 466(4): 629-36, 2015 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-26367180

RESUMEN

Thaumatin-like proteins (TLPs) are found in diverse eukaryotes. Plant TLPs, known as Pathogenicity Related Protein (PR-5), are considered fungal inhibitors. However, genes encoding TLPs are frequently found in fungal genomes. In this work, we have identified that Moniliophthora perniciosa, a basidiomycete pathogen that causes the Witches' Broom Disease (WBD) of cacao, presents thirteen putative TLPs from which four are expressed during WBD progression. One of them is similar to small TLPs, which are present in phytopathogenic basidiomycete, such as wheat stem rust fungus Puccinia graminis. Fungi genomes annotation and phylogenetic data revealed a larger number of TLPs in basidiomycetes when comparing with ascomycetes, suggesting that these proteins could be involved in specific traits of mushroom-forming species. Based on the present data, we discuss the contribution of TLPs in the combat against fungal competitors and hypothesize a role of these proteins in M. perniciosa pathogenicity.


Asunto(s)
Agaricales/genética , Agaricales/patogenicidad , Cacao/microbiología , Proteínas Fúngicas/genética , Genoma Fúngico , Enfermedades de las Plantas/microbiología , Secuencia de Aminoácidos , Proteínas Fúngicas/fisiología , Expresión Génica , Datos de Secuencia Molecular , Familia de Multigenes , Filogenia , ARN de Hongos/genética , Homología de Secuencia de Aminoácido , Virulencia/genética , Virulencia/fisiología
12.
Curr Genet ; 61(2): 185-202, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25614078

RESUMEN

Transposons are an important source of genetic variation. The phytopathogen Moniliophthora perniciosa shows high level of variability but little is known about the role of class I elements in shaping its genome. In this work, we aimed the characterization of a new gypsy/Ty3 retrotransposon species, named MpSaci, in the M. perniciosa genome. These elements are largely variable in size, ranging from 4 to 15 kb, and harbor direct long terminal repeats (LTRs) with varying degrees of similarity. Approximately, all of the copies are non-autonomous as shifts in the reading frame and stop codons were detected. Only two elements (MpSaci6 and MpSaci9) code for GAG and POL proteins that possess functional domains. Conserved domains that are typically not found in retrotransposons were detected and could potentially impact the expression of neighbor genes. Solo LTRs and several LARDs (large retrotransposon derivative) were detected. Unusual elements containing small sequences with or without interruptions that are similar to gag or different pol domains and presenting LTRs with different levels of similarities were identified. Methylation was observed in MpSaci reverse transcriptase sequences. Distribution analysis indicates that MpSaci elements are present in high copy number in the genomes of C-, S- and L-biotypes of M. perniciosa. In addition, C-biotype isolates originating from the state of Bahia have fragments in common with isolates from the Amazon region and two hybridization profiles related to two chromosomal groups. RT-PCR analysis reveals that the gag gene is constitutively expressed and that the expression is increased at least three-fold with nutrient depravation even though no new insertion were observed. These findings point out that MpSaci collaborated and, even though is primarily represented by non-autonomous elements, still might contribute to the generation of genetic variability in the most important cacao pathogen in Brazil.


Asunto(s)
Agaricales/genética , Genoma Fúngico , Filogenia , Retroelementos/genética , Agaricales/patogenicidad , Secuencia de Aminoácidos , Brasil , Cacao/microbiología , Humanos , Sistemas de Lectura Abierta , Alineación de Secuencia
13.
Fungal Genet Biol ; 76: 78-92, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25683379

RESUMEN

Wood decay mechanisms in Agaricomycotina have been traditionally separated in two categories termed white and brown rot. Recently the accuracy of such a dichotomy has been questioned. Here, we present the genome sequences of the white-rot fungus Cylindrobasidium torrendii and the brown-rot fungus Fistulina hepatica both members of Agaricales, combining comparative genomics and wood decay experiments. C. torrendii is closely related to the white-rot root pathogen Armillaria mellea, while F. hepatica is related to Schizophyllum commune, which has been reported to cause white rot. Our results suggest that C. torrendii and S. commune are intermediate between white-rot and brown-rot fungi, but at the same time they show characteristics of decay that resembles soft rot. Both species cause weak wood decay and degrade all wood components but leave the middle lamella intact. Their gene content related to lignin degradation is reduced, similar to brown-rot fungi, but both have maintained a rich array of genes related to carbohydrate degradation, similar to white-rot fungi. These characteristics appear to have evolved from white-rot ancestors with stronger ligninolytic ability. F. hepatica shows characteristics of brown rot both in terms of wood decay genes found in its genome and the decay that it causes. However, genes related to cellulose degradation are still present, which is a plesiomorphic characteristic shared with its white-rot ancestors. Four wood degradation-related genes, homologs of which are frequently lost in brown-rot fungi, show signs of pseudogenization in the genome of F. hepatica. These results suggest that transition toward a brown-rot lifestyle could be an ongoing process in F. hepatica. Our results reinforce the idea that wood decay mechanisms are more diverse than initially thought and that the dichotomous separation of wood decay mechanisms in Agaricomycotina into white rot and brown rot should be revisited.


Asunto(s)
Agaricales/genética , Evolución Molecular , Genoma Fúngico , Madera/microbiología , Agaricales/enzimología , Agaricales/patogenicidad , Lignina/metabolismo , Filogenia , Análisis de Secuencia de ADN
14.
Fungal Biol ; 128(3): 1758-1770, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38796260

RESUMEN

Starting in the fall of 2019, mortality, blight symptoms, and signs of white fungal mycelia were observed on external host tissues of non-native landscape trees as well as numerous native trees, understory shrubs, and vines throughout northern and central Florida, USA. We determined that the fungus is an undescribed species of Basidiomycota based on morphological characteristics and DNA sequence analysis. Phylogenetic analyses of the internal transcribed spacer (ITS), large subunit (LSU), and translation elongation factor 1-alpha (tef1) regions revealed that this novel plant pathogen is an undescribed taxon of the genus Parvodontia (Cystostereaceae, Agaricales). We propose the name Parvodontia relampaga sp. nov. which describes its unique morphological features and phylogenetic placement. We confirmed the pathogenicity of P. relampaga in greenhouse inoculations on host plants from which strains of this novel pathogen were isolated, including the non-native gymnosperm Afrocarpus falcatus, the non-native and commercially important Ligustrum japonicum, and the native tree Quercus hemisphaerica. P. relampaga was also detected on a total of 27 different species of woody host plants, including such economically and ecologically important hosts as Fraxinus, Ilex, Magnolia, Persea, Prunus, Salix, Vitis, and Vaccinium. For this new plant disease, we propose the name "relampago blight," which refers to the lightning-like rhizomorph growth (relámpago means 'lightning' in Spanish). This study presents a newly discovered fungal taxon with a wide host range on both angiosperms and gymnosperms that may be an emerging pathogen of concern in Florida and the Gulf Coast region.


Asunto(s)
ADN de Hongos , Filogenia , Enfermedades de las Plantas , Enfermedades de las Plantas/microbiología , Florida , ADN de Hongos/genética , Agaricales/genética , Agaricales/clasificación , Agaricales/aislamiento & purificación , Agaricales/fisiología , Agaricales/patogenicidad , Análisis de Secuencia de ADN , ADN Espaciador Ribosómico/genética , ADN Espaciador Ribosómico/química
15.
Biosci Biotechnol Biochem ; 77(8): 1779-81, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23924717

RESUMEN

The absolute configuration of strophasterol B (1) isolated from the fruiting bodies of Stropharia rugosoannulata was determined by an X-ray crystallographic analysis. Three compounds (2 to 4) were isolated from the mushroom which suppressed or promoted lettuce growth.


Asunto(s)
Agaricales/química , Cuerpos Fructíferos de los Hongos/química , Esteroides/química , Triterpenos/química , Agaricales/patogenicidad , Cristalografía por Rayos X , Estructura Molecular , Esteroides/aislamiento & purificación
16.
Medicina (B Aires) ; 73(5): 406-10, 2013.
Artículo en Español | MEDLINE | ID: mdl-24152394

RESUMEN

In Facultad de Ciencias Exactas y Naturales,Universidad de Buenos Aires there is a service called Servicio de Identificación de Hongos Tóxicos, directed by researchers of the Program of Medicinal Plants and Fungi Involved in Biological Degradation (PROPLAME-PRHIDEB, CONICET) that assist hospitals and other health establishments, identifying the different samples of fungi and providing information about their toxicity, so that patients can receive the correct treatment. The objective of the present study was to analyze all the cases received from 1985 to 2012. This analysis permitted the confection of a table identifying the most common toxic species. The information gathered revealed that 47% of the patients were under 18 years of age and had eaten basidiomes; the remaining 53% were adults who insisted that they were able to distinguish edible from toxic mushrooms. Chlorophyllum molybdites turned out to be the main cause of fungal intoxication in Buenos Aires, which is commonly confused with Macrolepiota procera, an edible mushroom. In the second place Amanita phalloides was registered, an agaric known to cause severe symptoms after a long period of latency (6-10 hours), and which can lead to hepatic failure even requiring a transplant to prevent severe internal injuries or even death, is not early and correctly treated.


Asunto(s)
Agaricales/clasificación , Intoxicación por Setas , Adolescente , Adulto , Agaricales/patogenicidad , Amanita/clasificación , Amanita/patogenicidad , Argentina , Femenino , Humanos , Masculino , Micotoxinas/análisis , Factores de Tiempo , Adulto Joven
17.
Biochemistry ; 50(45): 9901-10, 2011 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-21999603

RESUMEN

The necrosis- and ethylene-inducing peptide 1 (NEP1)-like proteins (NLPs) are proteins secreted from bacteria, fungi and oomycetes, triggering immune responses and cell death in dicotyledonous plants. Genomic-scale studies of Moniliophthora perniciosa, the fungus that causes the Witches' Broom disease in cacao, which is a serious economic concern for South and Central American crops, have identified five members of this family (termed MpNEP1-5). Here, we show by RNA-seq that MpNEP2 is virtually the only NLP expressed during the fungus infection. The quantitative real-time polymerase chain reaction results revealed that MpNEP2 has an expression pattern that positively correlates with the necrotic symptoms, with MpNEP2 reaching its highest level of expression at the advanced necrotic stage. To improve our understanding of MpNEP2's molecular mechanism of action, we determined the crystallographic structure of MpNEP2 at 1.8 Å resolution, unveiling some key structural features. The implications of a cation coordination found in the crystal structure were explored, and we show that MpNEP2, in contrast to another previously described member of the NLP family, NLP(Pya) from Pythium aphanidermatum, does not depend on an ion to accomplish its necrosis- and electrolyte leakage-promoting activities. Results of site-directed mutagenesis experiments confirmed the importance of a negatively charged cavity and an unforeseen hydrophobic ß-hairpin loop for MpNEP2 activity, thus offering a platform for compound design with implications for disease control. Electron paramagnetic resonance and fluorescence assays with MpNEP2 performed in the presence of lipid vesicles of different compositions showed no sign of interaction between the protein and the lipids, implying that MpNEP2 likely requires other anchoring elements from the membrane to promote cytolysis or send death signals.


Asunto(s)
Agaricales/química , Agaricales/patogenicidad , Cacao/microbiología , Proteínas Fúngicas/química , Enfermedades de las Plantas/microbiología , Agaricales/genética , Agaricales/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Secuencia de Bases , Cristalografía por Rayos X , Cartilla de ADN/genética , Etilenos/biosíntesis , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Electricidad Estática , Nicotiana/microbiología
18.
Mol Plant Microbe Interact ; 24(7): 839-48, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21405988

RESUMEN

Oxalic acid (OA) and Nep1-like proteins (NLP) are recognized as elicitors of programmed cell death (PCD) in plants, which is crucial for the pathogenic success of necrotrophic plant pathogens and involves reactive oxygen species (ROS). To determine the importance of oxalate as a source of ROS for OA- and NLP-induced cell death, a full-length cDNA coding for an oxalate decarboxylase (FvOXDC) from the basidiomycete Flammulina velutipes, which converts OA into CO(2) and formate, was overexpressed in tobacco plants. The transgenic plants contained less OA and more formic acid compared with the control plants and showed enhanced resistance to cell death induced by exogenous OA and MpNEP2, an NLP of the hemibiotrophic fungus Moniliophthora perniciosa. This resistance was correlated with the inhibition of ROS formation in the transgenic plants inoculated with OA, MpNEP2, or a combination of both PCD elicitors. Taken together, these results have established a pivotal function for oxalate as a source of ROS required for the PCD-inducing activity of OA and NLP. The results also indicate that FvOXDC represents a potentially novel source of resistance against OA- and NLP-producing pathogens such as M. perniciosa, the causal agent of witches' broom disease of cacao (Theobroma cacao L.).


Asunto(s)
Agaricales/metabolismo , Agaricales/patogenicidad , Carboxiliasas/biosíntesis , Nicotiana , Ácido Oxálico/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Carboxiliasas/genética , Muerte Celular , Flammulina/enzimología , Flammulina/genética , Formiatos/metabolismo , Necrosis , Enfermedades de las Plantas/microbiología , Hojas de la Planta/microbiología , Plantas Modificadas Genéticamente , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Nicotiana/genética , Nicotiana/metabolismo , Nicotiana/microbiología
19.
Public Health Rep ; 126(6): 844-52, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22043100

RESUMEN

OBJECTIVE: Exposure to wild mushrooms can lead to serious illness and death. However, there is little information on the epidemiology of mushroom exposures nationwide, as there is no specific surveillance for this outcome. We described mushroom exposures in Florida using available data sources. METHODS: We performed a population-based study of mushroom exposure calls to the Florida Poison Information Center Network (FPICN) and cases of mushroom poisoning reported in hospital inpatient and emergency department (ED) data from 2003 through 2007. RESULTS: There were 1,538 unduplicated mushroom exposures reported during this period, including 1,355 exposure calls and 428 poisoning cases. Most exposures reported to FPICN occurred in children ≤6 years of age (45%) and males (64%), and most were unintentional ingestions (60%). Many exposures resulted in no effect (35%), although 21% reported mild symptoms that resolved rapidly, 23% reported prolonged/systemic (moderate) symptoms, and 1% reported life-threatening effects. Most calls occurred when in or en route to a health-care facility (43%). More than 71% of poisonings identified in hospital records were managed in an ED, and most occurred in young adults 16-25 years of age (49%), children ≤6 years of age (21%), adults >25 years of age (21%), and males (70%). No deaths were reported. CONCLUSIONS: Combined, these data were useful for describing mushroom exposures. Most exposures occurred in males and in young children (≤6 years of age) and young adults (16-25 years of age), with 78% resulting in contact with a health-care facility. Education should target parents of young children-especially during summer, when mushrooms are more abundant-and young adults who are likely experimenting with mushrooms for their potential hallucinogenic properties.


Asunto(s)
Agaricales/patogenicidad , Intoxicación por Setas/epidemiología , Centros de Control de Intoxicaciones/estadística & datos numéricos , Adolescente , Adulto , Agaricales/clasificación , Factores de Edad , Niño , Preescolar , Exposición a Riesgos Ambientales/efectos adversos , Exposición a Riesgos Ambientales/estadística & datos numéricos , Femenino , Florida/epidemiología , Humanos , Lactante , Recién Nacido , Masculino , Vigilancia de la Población/métodos , Factores Sexuales , Adulto Joven
20.
Genet Mol Res ; 10(1): 326-34, 2011 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-21365548

RESUMEN

We evaluated the genetic and physiological variability of Moniliophthora perniciosa obtained from healthy and diseased branches of cacao (Theobroma cacao) plants. The diversity of the isolates was evaluated by RAPD technique and by studies of virulence and exoenzyme production. The genetic variability of endophytic and pathogenic M. perniciosa was evaluated in association with pathogenicity assays. RAPD analysis showed eight genetic groups, which were not related to plant disease status (healthy versus diseased branches). Isolates from cacao were included in three groups, excluding isolates from other host plants. Pathogenicity and enzyme analysis showed that the virulence of the isolates is not related to exoenzyme production. This is the first evidence that M. perniciosa colonizes healthy parenchymatic tissues, showing that endophytic behavior may occur in this species.


Asunto(s)
Agaricales/genética , Agaricales/patogenicidad , Cacao/microbiología , Enfermedades de las Plantas/microbiología , Agaricales/clasificación , Variación Genética/genética , Técnica del ADN Polimorfo Amplificado Aleatorio
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA